1. Field of the Invention
The present invention relates to an information medium equipped with a case body that rotatably houses a tape reel, a lid that opens and closes a withdrawal opening of the case body, and a coil spring that energizes the lid.
2. Description of the Related Art
As one example of this type of information medium, a tape cassette disclosed by Japanese Laid-Open Patent Publication No. 2002-367327 is known. This tape cassette is constructed by rotatably disposing hubs around which a magnetic tape has been wound inside a cassette case including an upper shell and a lower shell. A lid that protects the magnetic tape is pivotally supported on a front surface of the cassette case. A torsion coil spring that energizes the lid towards a closed position is disposed between the lid and the upper shell and when the tape cassette is not in use (i.e., when the tape cassette has been ejected from a recording/reproducing apparatus), the front surface of the cassette case is covered by the lid due to the energizing force of the torsion coil spring.
As another example of this type of information medium, a tape cassette is disclosed by the present applicant in Japanese Laid-Open Patent Publication No. H07-320448. In this tape cassette also, like the tape cassette described above, a lid is pivotally disposed at the front surface of a case body (which corresponds to the “cassette case” of the tape cassette described above), and the lid is energized by a lid spring (which corresponds to the “torsion coil spring” of the tape cassette described above). Since a linear foot portion of the lid spring (i.e., one of the “hooking arms” for the tape cassette described above) is cut during the manufacturing process of the lid spring, burrs are sometimes produced on the end surface of the foot portion. When using this type of lid spring, there is the risk of the burrs catching on the upper case that is engaged by the end of the foot portion (the “upper shell” for the tape cassette described above), resulting in defective operation of the lid. For this reason, in the tape cassette described above, to avoid contact between the end surface of the foot portion and the upper case, the end of the foot portion of the lid spring (referred to as the “end portion (25)” in the former publication and the “end” in the latter publication) is bent back.